Successful weight-loss intervention before infection associated with 60% lower risk of severe disease in patients with obesity. A Cleveland Clinic study shows that among patients with obesity, prior weight loss achieved with bariatric surgery was associated with a 60% lower risk of developing severe complications from COVID-19 infection. The research was published in the journal JAMA Surgery.

Numerous studies have established obesity as a major risk factor for developing serious illness from an infection of SARS-CoV-2, the virus that causes COVID-19. Obesity weakens the immune system, creates a chronic inflammatory state, and increases risk for cardiovascular disease, blood clots, and lung conditions. All of these conditions can complicate COVID-19.

The aim of this study was to examine whether a successful weight-loss intervention in patients with obesity prior to contracting COVID-19 could reduce the risk of developing a severe form of this disease.

A total of 20,212 adult patients with obesity were included in this observational study. A group of 5,053 patients with a body mass index (BMI) of 35 or greater who had weight-loss surgery between 2004 and 2017 were carefully matched 1:3 to non-surgical patients, resulting in 15,159 control patients. Compared with those in the non-surgical group, patients who had bariatric surgery lost 19% more body weight prior to March 1, 2020 (the beginning of the COVID-19 outbreak in Cleveland).

After the COVID-19 outbreak, researchers looked at four COVID-19-related outcomes: rate of contracting SARS-CoV-2 infection, hospitalization, need for supplemental oxygen and severe disease (defined as a combination of ICU admission, need for mechanical ventilation or death).

Although the rate of contracting SARS-CoV-2 was similar between the groups (9.1% in the surgical group and 8.7% in the non-surgical group), participants in the weight-loss surgery group experienced much better outcomes after contracting COVID-19 compared with those in the non-surgical group. Researchers found that patients with prior weight loss surgery had a 49% lower risk of hospitalization, 63% lower risk of need for supplemental oxygen, and 60% lower risk of developing severe COVID-19.

Although the exact underlying mechanisms are not known, these data suggest that patients who underwent weight-loss surgery were healthier at the time of contracting a SARS-CoV-2 infection, which resulted in better clinical outcomes.

Release date: 16 December 2021
Source: Cleveland Clinic